The role of automatic dishwashing is twofold: to clean soiled dishware and to leave it shiny. Typically when water dries from surfaces water-marks, smears and/or spots are left behind. These water-marks may be due to the evaporation of water from the surface leaving behind deposits of minerals which were present as dissolved solids in the water, for example calcium, magnesium and sodium ions and salts thereof or may be deposits of water-carried soils, or even remnants from the cleaning product. During the course of this work, it has been observed that this problem can be exacerbated by some cleaning compositions which modify the surface of the dishware during the automatic dishwashing process such that after rinsing, discrete droplets or beads of water remain on the surface instead of draining off. These droplets or beads dry to leave noticeable spots or marks known as water-marks. This problem is particularly apparent on ceramic, stainless steel, plastic, glass and painted surfaces. The problem is more acute when the water used in the automatic dishwasher is hard water.
The object of the present invention is to provide an automatic dishwashing method that leaves the washed dishware shiny and with reduced incidence or free of spots.